A method and testing container for detecting the presence of certain components or substances in biological fluids is disclosed in U.S. Pat. No. 3,036,894. The testing container has a flexible tubular body with non-communicating individual compartments, some of which contain reagents, which allow for transfer of the contents of the preceding compartment to a succeeding compartment. The substance to be tested is passed sequentially through each compartment and intermixed with the substances contained therein until it reaches the final compartment where the tested substance can be removed for test reading and conclusion.
A small testing tube for the chemical analysis of gas compositions is disclosed in U.S. Pat. No. 3,022,141. The testing tube disclosed therein contains three or more separately arranged reagents or layers of reagents, one or more reagents are placed in one or more breakable ampoules. The testing tubes are breakable in the area of the ampoules but are provided with a flexible reinforcing coating. The gas flows through the testing tube contacting each reagent in sequence and finally reaches the indicator layer where the presence of the particular component is detected. Both ends of the testing tube are sealed and are broken just prior to testing.
Another method for measuring gas, vapor and aerosol components in an air sample using a glass testing tube is disclosed in U.S. Pat. No. 4,300,910. The disclosed testing tube has a breakable tip at each end and contains a breakable ampoule, an entraining filter, a reaction layer, an empty tube chamber and a liquid lock in that order. As the gas passes through the testing tube, the particles are entrained by the filter. The ampoule is broken to direct a solvent through the filter to dissolve the materials and to pass them into a reaction layer where a color reaction takes place. The color reaction is visible in the empty chamber and indicates which components are present in the air sample.
There is a need for a simple chemical test method and kit which can be used in the field by a relatively untrained person to determine whether the oil in a transformer has been contaminated with polychlorinated biphenyl [hereinafter sometimes referred to as PCB] in excess of the Environmental Protection Agency regulations. There are currently an estimated 20,000,000 transformers which will have to be analyzed for polychlorinated biphenyl contamination in order to comply with the current regulations. Many of these units are PCB-free, that is, they contain less than 50 ppm of PCB's. The method and chemical test kit of the present invention could eliminate the necessity of costly laboratory analysis on about 60% of these transformers.